1. Field of the Invention
The present invention relates to the cleaning of optical fiber connectors, particularly to the cleaning of in-adapter optical fiber connectors, and more particularly, to ultrasound apparatus for cleaning optical fiber connectors.
2. Background Art
In a typical optical fiber connector, an optical fiber has a terminal portion which has a side wall surrounded by a ferrule. An adapter is needed to couple the light from the fiber in one connector to the fiber in another connector. A pair of connector ferrules can be accurately aligned face to face via the sleeve inside the adapter. An in-adapter connector, i.e., an assembly with a connector that is plugged into an adapter, is typically referred to as a “female” connector, whereas a free connector which is not in an adapter is typically referred to as a “male” connector. Female connectors can exist in many fiber optic systems and equipment, e.g. on connector rack panels or instrument front panels. In these cases, one side of the adapter is linked with an internal fiber connector, which is relatively permanent, whereas the other side of the adapter which faces the outside is for external fiber connectors.
The ferrule-sleeve connection system has been implemented in various types of standard and non-standard optical fiber connectors. Some examples of conventional ferrule-sleeve connector systems include FC, SC, ST, LC, MU, MT-RJ, etc, in which there can be PC (physical contact) type or APC (angled physical contact) type of connections.
During the use of optical fiber communications equipment, various contaminants including dust, finger oils, and grease may accumulate in optical fiber connectors and settle on fiber and ferrule end surfaces. Contaminants may be carried by ambient air or introduced to the fiber and ferrule end surfaces by the hands of a human operator, for example. The presence of such contaminants may significantly attenuate or even completely block the transmission of optical signals through the optical fiber connectors, or cause undesirable reflection of optical signals, thereby significantly degrading the performance of the optical fiber telecommunications equipment.
A few conventional methods have been used in the industry to clean male connectors. For example, it has been common practice in the industry to use cotton swabs or foam swabs with a solvent such as alcohol. Another common tool, especially useful for field applications, is a cleaning cassette with a replaceable reel of cloth tape. A cleaning operation for each connector requires the use of a new section of the cloth. A disadvantage associated with the above methods is that some residual cleaner materials such as cotton fibers may remain on the connectors. Furthermore, they cannot be conveniently used for female connector cleaning.
In a conventional cleaning operation for a female connector, a user typically needs to first unplug the connector from the adapter, i.e., to convert the female connector to a male connector. This conversion is typically very inconvenient and time consuming. For example, to clean a female connector on an instrument panel, the user needs to open the instrument box, unplug the internal fiber connector from the inner side of the adapter, clean the connector ferrule surface, replug it back to the adapter, and then close the instrument box. Attempts have been made to avoid opening the box by using adhesive sticks or adhesive tapes in a cartridge to stick out contaminants from the female connector surface through the adapter. However, this method is usually ineffective and costly. During the cleaning operation, it is desirable that the user be very careful not to re-contaminate the connector system.
Therefore, there is a need for an improved apparatus for cleaning optical fiber connector systems for highly efficient removal of various types of contaminants within a short time and easy adaptation to different types of connectors, especially when the connectors are in-adapter female connectors.